The present invention relates to a system for braking a vehicle, more especially an aircraft running over the ground, as well as an anti-locking regulator for this braking system.
So as to prevent braked wheels from locking, aircraft braking systems comprise an anti-locking regulator for regulating the slippage, i.e. in reality servo-controlling the speed, of braked wheels. Such a regulator behaves like a filter capable, at least partially, of eliminating the parasite periodic signals tending to impair the regulation and of reinforcing the signals favorable thereto.
In known braking systems, the anti-locking regulator is formed by an analog device which receives analog signals representative, on the one hand, of the speed of a braked wheel and, on the other, of a reference speed such as the speed of an unbraked wheel and which sends a control signal to an electrohydraulic servovalve actuating the brakes. Such analog anti-locking regulators must be adapted to each type of brake or wheel used; in addition, because of the dispersion of the characteristics of their components, they require delicate adjustments. Furthermore, they cannot accomodate all the parameters coming into play during the braking of an aircraft, without extreme material complication.
To overcome these drawbacks, it would therefore be advantageous to replace these analog anti-locking regulators by digital anti-locking regulators which could be integrated with a processor. However, although digital tachometric sensors are at present known, the digital construction of anti-locking regulators raises technical difficulties, for it is not possible, as will be seen further on, to transpose analog anti-locking regulators purely and simply into digital form.